The city of Spokane has bought 1.8 acres of land that includes a former Kar Brite car wash site, at 902 E. Sprague, for future development as part of its storm-water retention system.

The city bought the property for $756,000 from Michael and Joy Chastek, a Spokane couple, city documents show. Mark McLees and Mark Davis, both of NAI Black, of Spokane, handled the transaction.

City spokeswoman Marlene Feist says the city intends to raze the structures there, and already has removed gas pumps and the awnings that covered them from the property. The 6,600-square-foot car-wash building and a 5,300-square-foot storage building behind it that partially collapsed during last winter's heavy snows will be removed by spring, she says.

The city plans to build within the next five years a 1- to 2-million-gallon underground retention tank on the property to hold runoff water from heavy rainstorms and snowmelt, Feist says.

Runoff can increase flows in the city's combined wastewater and storm-water sewer systems so much that they exceed the capacity of the city's sewage-treatment plant and enter the Spokane River untreated, the city says.

It's expected that the tank will cost about $4 million to $ 5 million, Feist says. The tank will be one of at least 25 such retention tanks the city's wastewater department intends to develop throughout the city.

Another storage garage on the property, which has about about 3,000 square feet of floor space, will remain on the site until the city begins construction of the retention tank.

The city has yet to determine whether anything else can be built at the site once the tank is in place, Feist says. Any development, she says, would be limited.